That's basically what happened with Pathfinder when they introduced the Shifters class in Ultimate Wilderness. The class was useless Most of the book wasn't really worth using except for the archtypes, and the information on familiars. Shortly after that we got Pathfinder 2nd Edition that long time fans hate yet the people who watch youtube celebs play RPG's love.
While some people out there may think E-Celebs could ruin RPG's going forward, I believe that we'll see higher quality books come out from smaller studios wanting to fill in a niche left by the "popular" games. Similar to how Paizo filled in the 3.5 niche when 3.5 died to give way to 4th Edition.
I'm on a bit more of a doomer bent, with this one. For context, I started with 3.5 because it was the only groups I could find as a Lil Babby. Even at the point I was playing, with my wide-eyed, D&D optimism, I was sick of OGL spin offs. Everything was a bad OGL cash grab. Farscape d20. Game of Thrones d20. Wizards began engaging in even more scummy tactics - they had a fondness for sneakily buying up other properties, renaming them, and then providing multiple statlines.
Swashbuckler Adventures (I think was the name) was their attempt to nip 7th Sea in the bud, which somewhat worked. Sure, it provided stats for the d20 and RnK rulesets, but what were you more likely to find, a game of 7th Sea, or 'Why don't we just run a pirate/swashbuckling adventure in D&D using these rules?' via Lingua Franca. Same with Oriental Adventures, which was Wizard's attempt to sneak into the L5R market.
Looking back, while I wasn't a huge fan of 4e (I preferred it to 3.5, but I'm not a fan of D&D), one of the best things which came out of it was the explosion of non-d20 games. It was through that I discovered Savage Worlds and GURPS, Exalted, Weapons of the Gods/Legends of the Wulin, Fate.
But this is either going to get much worse before it gets better, or gaming will just be changed or very strongly divided. With the rise of eCelebs like Critical Role, the stranglehold D&D already had is just going to get worse, and this isn't just limited to D&D.
Currently, the most popular games on my Discords and Roll20 are PbtA in general, Lancer (4e base, written by a far left commie who's intentionally baked the mechanics heavily into the setting to make it -very- hard to play outside of it without gutting the whole system), D&D 5e and Call of Cthulhu 7e. While I get CoC is popular on it's own, I wondered why people were so big on it, like when I saw on Reddit that Monsterhearts was hugely popular out of no-where. To my lack of surprise, Monsterhearts and Call of Cthulhu were both played on Critical Role. To the point just a single episode on Critical Role -completely backlogged the developers warehouses with orders overnight-.
At it's core, the two big issues I see is that 5e is going to be 3.5 on steriods. It's already happened with a lot of games. Star Wars 5e, a fanhack, is more popular than FFG Star Wars. The One Ring (which is actually getting a 2e, which is nice) was cancelled to make a 5e adaptation, because people just wouldn't play it otherwise. This is most likely going to make up the normie, medium crunch groups.
But on the other hand, PbtA has become the shitty, SJW OGL of gaming. Every single game you find is generally the same premise, with the descriptions changed 'When you want to
go aggro' becomes 'When you want to
do a cringeworthy assault that leaves your enemies in the dust...') but is also picked up by the mainstream Twitter circle jerks for self-promotion. I've seen OSR making little footnotes, but even then, the few I see which really get pushed are immensely ruleslite (Mork Borg) which are picked up by mainstream media because 'Swedish roleplaying game'.
Even the games which are pretty good (Blades in the Dark, Apocalypse World I'm not a fan of, but it's kinda' cute design-wise) are not the issue themselves, but these major OGLs are now the gatekeepers to gaming. Blades in the Dark never touched the 'muh gender' stuff directly, or ever mentioned it, but you won't find a single Forged in the Dark game (Scum and Villainy, which I'm pretty sure is written by a troon), Girl by Moonlight (multiple games about being magical girls. Based around 'who you are, what you believe and the power of relationships and community against an oppress society) which doesn't contain this stuff to the hilt.
Twitter is how these things are going to advertise. These are then picked up by CritRoles, which have to toe the line to not get removed, which then become the advertisement, while other indie games will get left in the dirt. Writing a Kickstarter game about troons in PbtA fighting penguins will not only be signal boosted within the community (as they all fund each other), but if you're lucky, picked up by Twitter and pushed further and with the low effort artwork needed? All you need is some basic writing, some rules made by copy-pasting OGL and you're sorted.
Even if CoC has resisted something like this till now, a large influx of people into the hobby are going to come from the same circles. And after years of being 'D&Ds less popular cousin', you think developers like that are gonna ignore the ability for a 2hr Youtube video by a bunch of voice actors to single-handedly increase their sales more than x5 what they've sold in the last ten years, when all they have to do is write 'Well, Lovecraft is a racist and Eldritch Horror is for all genders!' at the front of the book?
/end grumpy sperg ramble.